Functional Counter

module cntr(q, aclr, clk, func, d);

input aclr, clk;

input [7:0] d;

input [1:0] func; // Controls the functionality

output [7:0] q;

reg [7:0]q;

always @(posedge clk or posedge aclr) begin

if (aclr)

q <= 8'h00;

else

case (func)

2'b00: q <= d; // Loads the counter

2'b01: q <= q + 1; // Counts up

2'b10: q <= q - 1; // Counts down

2'b11: q <= q;

endcase

end

endmodule